Thermal regulation system for at least one electronic module embedded onboard an aircraft

ABSTRACT

Heat regulation system ( 1 ) for at least one equipment item ( 2 ) embedded onboard an aircraft, includes a thermal regulation circuit ( 5 ) connected to the equipment item(s) ( 2 ). The thermal regulation circuit ( 5 ) includes a modular thermal regulation device ( 6 ) adapted to receive a modifiable number of thermal regulation modules ( 8 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thermal regulation system for at least one electronic module embedded onboard an aircraft.

2. Description of the Related Art

The so-called “embedded” electronic hardware is often required to operate in difficult conditions notably of vibration, impacts, humidity, acceleration, and confinement (problems of heat and overheating).

These difficult conditions tend to cause operating faults in such electronic hardware, despite all the precautions taken in their design and their production. This leads to such electronic hardware being designed to favour trouble-shooting and maintenance thereof, and, to this end, such electronic hardware has to meet new standards.

The electronic hardware used onboard aircraft, with a view notably to facilitating the exchange of defective hardware, implement one of the new standards cited above provides for producing such electronic hardware (often referred to by the term “modular avionics”) in the form of modular structures, called LRM, an acronym standing for “line replaceable module”.

Such modular structures, hereinafter in the description called electronic modules, are formed in the form of units, generally installed in racks that combine a large number of such electronic modules. Obviously, in smaller aircraft, such as small aeroplanes or helicopters, the racks are smaller, even non-existent, and the electronic modules are distributed at different points of the aircraft.

This is favourable in terms of simplifying maintenance, handling and rapid trouble-shooting, but tends to make it more difficult to discharge the heat produced by the various components contained in the modules. Furthermore, the electronic components used are increasingly sophisticated and tend to produce more and more thermal energy that is difficult to discharge. Systems are known that are centralized in an aircraft, generally distributing air, more rarely liquid, to the equipment items, to regulate their temperature. Such a system is complex, notably with regard to the distribution lines which are bulky and very long between the cooling plant, or ECS, an acronym for “Environment Control System”, and the equipment items. Furthermore, the equipment items, notably the electronic modules for high power levels or hotspots, are noisy because of the high air velocities in the ducts.

Local systems are also known that are based on fans, generally redundant, which lack reliability and create high pollution risks because of the circulation of the air directly over the components. Furthermore, the air is released locally and can overheat the areas concerned (self-overheating). These systems can also be noisy in high power cases (fan and air noise).

The increasing power in high-density components (multicore processors, fpga) creates hotspots, the cooling of which is no longer compatible with centralized or local standard air cooling systems. A portion of the power has to be diverted to be dissipated in more suitable remote areas (size, noise, natural cold spots, etc.).

SUMMARY OF THE INVENTION

One aim of the invention is to mitigate these problems.

One aim of the invention is to provide an adjustable thermal regulation system, that can be adapted to any type of aircraft, such as an airliner, a small aeroplane or a helicopter.

According to one aspect of the invention, there is proposed a thermal regulation system for at least one equipment item embedded onboard an aircraft, comprising:

a thermal regulation circuit external to said equipment item(s) and connected to said equipment item(s), said thermal regulation circuit comprising a modular thermal regulation device adapted to receive a modifiable number of thermal regulation modules of different kinds, the modular thermal regulation device comprising a frame adapted to receive a modifiable number of thermal regulation modules;

Said thermal regulation circuit comprising at least one thermal connector connected to an embedded electronic module.

Such a system makes it possible, at lower cost, to propose a thermal regulation system that is modular according to the equipment of the aircraft, and that can be adapted to the size of the aircraft. For example, it is equally adapted to an aircraft of large size, and to a small aircraft or a helicopter.

The modular thermal regulation device can, for example, comprise a base or rack or frame capable of receiving a modifiable number of plug-in and removable thermal regulation modules. Thus, a supplier of electronic equipment can simultaneously supply its electronic function and the associated thermal regulation module, the assembly being qualified previously.

Thus, the modularity is easy to produce.

It is therefore advantageously possible to cool the hotspots of electronic modules generally comprising electronic boards provided with powerful processors locally generating very significant releases of heat. Such thermal connectors are, for example, described in the document FR2920946.

In one embodiment, the equipment item(s) comprise at least one electronic module.

A system according to one aspect of the invention is particularly well suited to thermal regulation for electronic modules that can release high levels of heat, and even generate hotspots.

In one embodiment, the system comprises at least one frame adapted to receive a modifiable number of embedded electronic modules.

Thus, the system is also well suited to large aircraft, generally comprising one or more frames adapted to receive a modifiable number of embedded electronic modules. Such a frame is, for example, described in the document FR2803166.

According to one embodiment, said thermal regulation circuit comprises a two-phase heat transfer fluid.

The use of such a two-phase heat transfer fluid makes it possible not to have means for circulating the heat transfer fluid, because the latter circulates by thermodynamic effect.

In one embodiment, at least one thermal regulation module comprises at least one condenser.

Such an embodiment makes it possible to transport heat with no external forces, and therefore with a lower energy consumption.

Furthermore, such systems are passive and therefore have a greater reliability (no wear elements).

As a variant, said regulation circuit comprises a heat transfer fluid.

For example, at least one thermal regulation module comprises at least one pump.

Such an embodiment is easier to design, and can cool modules of higher power by increasing the pump flow rate (redundancy is preferable to ensure a better reliability).

For example, at least one thermal regulation module comprises at least one compressor.

Such an embodiment makes it possible to create cold, unlike the previous systems which ensure a transfer of heat, the compressor system can, by thermodynamic effect, create cold with advantageous efficiency.

These compressor systems can be combined with the systems previously described, two-phase, or pumped systems for transportation.

As a variant, said thermal regulation circuit comprises air as heat transfer fluid.

For example, at least one thermal regulation module comprises at least one fan.

Such an embodiment makes it possible to use air which is the element most readily available onboard aircraft, so it may be interesting to create modular elements distributing air intended to cool the thermal connector.

According to another aspect of the invention, there is also proposed an aircraft comprising a system according to one of the preceding claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood on studying a few embodiments described as non-limiting examples, and illustrated by the attached drawings in which:

FIG. 1 schematically illustrates a system according to one aspect of the invention; and

FIGS. 2 to 5 illustrate variant embodiments of the invention.

In all the Figures, the elements that have identical references are similar.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically illustrates a thermal regulation system according to one aspect of the invention.

A thermal regulation system 1 for at least one electronic module 2 comprises, in the case in point, a single electronic module 2, and a frame or rack 3 adapted to receive a modifiable number of embedded electronic modules 2.

Such a frame is, for example, described in the French patent application FR2803166.

Obviously, the invention applies to any combination of several electronic modules 2.

As represented in FIG. 1, at bottom left, an electronic module 2 comprises a hotspot linked to a thermal connector 4, as described, for example, in the French patent application FR2929946.

Such a thermal connector makes it possible to have, upon a connection/disconnection, no loss of heat transfer fluid, because at the male/female interface of the connector, there is no exchange of fluid, because there is a loop on one side of the connector and another loop on the other.

If the heat transfer fluid is two-phase, a thermal connector 4 can include an evaporator.

The system also comprises a thermal regulation circuit 5 connected to the electronic module(s) 2, using a heat transfer fluid to regulate the temperature of the electronic modules 2, notably cool them, because the latter generally comprise electronic boards provided with powerful processors generating hotspots releasing a great quantity of heat.

In the example of FIG. 1, the equipment items represented are only independent electronic modules, or electronic modules that are grouped together on a frame 3, but, obviously, the thermal regulation circuit 5 can also be connected to any other equipment requiring thermal regulation.

The thermal regulation system 1 also comprises a modular device 6, that can, for example, comprise a base or rack 7 adapted to receive an adjustable or modifiable number of thermal regulation modules 8.

Obviously, all the elements of this system are controlled by an electronic control unit that is not represented in the Figure, for the feedback of information from a set of sensors, as conventionally in any thermal regulation system.

The thermal regulation system 1 therefore comprises a modular thermal regulation device 6 for which it is possible to adapt and/or modify the number of thermal regulation modules that it receives according to the number of equipment items to be thermally regulated.

Such a system can be linked to the thermal connectors 4 by heat transfer fluid circulation pipes or tubes of small section, which is particularly advantageous when the equipment items to be thermally regulated are located in areas that have little space available or when the equipment items to be thermally regulated are of small size. It is then possible to consider adapting the heat transfer fluid circulation pipes or tubes, like electric cables, along partitions or similar.

Such a system 1 makes it possible to facilitate maintenance, and can be made redundant to improve the availability and the reliability of the system.

In the case of replacement or addition of new equipment items, notably of electronic modules of increasingly greater power, therefore releasing increasing amounts of thermal energy, the system makes it possible to replace and/or add as many thermal regulation modules as necessary. For example, in the case of the addition of new equipment items 2, the latter can be linked to new thermal regulation modules 8 of the thermal regulation system 1, without the need for intensive intervention on the rest of the system 1.

A number of embodiments can be envisaged, notably dependent on the heat transfer fluid chosen, for the transportation mode (active or passive) and on the type of cooling (passive, exchanger or compressor). In other words, for one and the same heat transfer fluid, the thermal regulation modules 8 can be of different kinds, so it is possible to combine the following embodiments.

A first embodiment is illustrated in FIG. 2, for which the heat transfer fluid is a single-phase liquid, such as water or glycol. An element 2 to be thermally regulated is linked to the thermal regulation circuit 5 via the thermal connector 4, the thermal regulation circuit 5 linking the element 2 to a thermal regulation module 8. Since the heat transfer fluid is liquid, the thermal regulation module 8 can comprise at least one pump 9, in this case two pumps 9, as illustrated in FIG. 2.

This embodiment presents the advantage of allowing for significant energy dissipations with production simplicity, because there are pumps of different sizes according to the flow rates and head losses to be observed.

A second embodiment is illustrated in FIG. 3, for which the heat transfer fluid is pressurized air. An element 2 to be thermally regulated is linked to the thermal regulation circuit 5 via a thermal connector 4, the thermal regulation circuit 5 linking the element 2 to a thermal regulation module 8. Since the heat transfer fluid is pressurized air, the thermal regulation module 8 can comprise at least one fan 10, in this case two fans 10, as illustrated in FIG. 3.

This embodiment presents the advantage of not requiring any additional cooling circuit, the air being able to be tapped locally, and being available on all carriers.

A third embodiment is illustrated in FIG. 4 for which the heat transfer fluid can be a single-phase liquid or air.

The benefit of using a compressor is that it allows for an active cooling below room temperature, the transportation of the heat being performed by a single-phase liquid system or by air, the preceding embodiments requiring an active moving mechanism (pump or fans). An element 2 to be thermally regulated is linked to the thermal regulation circuit 5 via a thermal connector 4, the thermal regulation circuit 5 linking the element 2 to a thermal regulation module 8. Since the heat transfer fluid is liquid, the thermal regulation module 8 can comprise at least one compressor 11, in this case two compressors 11, as illustrated in FIG. 4.

This embodiment presents the advantage of being able to lower the cold point below room temperature.

A fourth embodiment is illustrated in FIG. 5, for which the heat transfer fluid is a two-phase system, for example, this system makes it possible to transport the heat from the dissipative elements to the cooler without requiring external force to move the fluid. An element 2 to be thermally regulated is linked to the thermal regulation circuit 5 via the thermal connector 4, in this case an evaporator, the thermal regulation circuit 5 linking the element 2 to a thermal regulation module 8. Since the heat transfer fluid is two-phase (liquid and gas), the thermal regulation module 8 can comprise at least one condenser 12, as illustrated in FIG. 5.

This embodiment, employing a passive two-phase thermal regulation circuit 5 with high conductivity of heat pipe or two-phase loop type presents the advantage of being totally passive, i.e. of not requiring any means for circulating the heat transfer fluid, this circulation being linked to thermal dynamics.

A thermal regulation system according to one aspect of the invention is easy to install and maintain.

Such a system also makes it possible to take account of the high power densities within a reduced footprint.

Such a system further makes it possible, in the case of the cooling of an equipment item, to separate the area in which the heat is dissipated from the area in which the cooling is performed, which makes it possible to have, in proximity to the equipment items, better environmental conditions for the equipment items. For example, if the case of a machine containing embedded equipment items exposed to the sun is taken, the ambient air and the structure are at very high temperatures, so it may be more advantageous to isolate the area of the equipment items and cool them with compressors that can be located at a certain distance from the hot sources via the thermal connectors.

Furthermore, in high humidity or salt mist conditions, it may be advantageous not to blow this air directly over the components, which would reduce their reliability, whereas the remote cooling system can be located in an area that is protected and connected by pipes to the dissipative element.

Such thermal regulation modules can be used in racks or be isolated, so they can be series manufactured, which limits the unit manufacturing cost. 

What is claimed is:
 1. Thermal regulation system for at least one equipment item embedded onboard an aircraft, comprising: a thermal regulation circuit external to said equipment item(s) and connected to said equipment item(s), said thermal regulation circuit comprising a modular thermal regulation device adapted to receive a modifiable number of thermal regulation modules of different kinds, the modular thermal regulation device comprising a frame adapted to receive a modifiable number of thermal regulation modules; and said thermal regulation circuit comprising at least one thermal connector connected to an embedded electronic module.
 2. System according to claim 1, in which the equipment item(s) comprise at least one electronic module.
 3. System according to claim 2, in which said thermal regulation circuit comprises a two-phase heat transfer fluid.
 4. System according to claim 3, in which at least one thermal regulation module comprises at least one condenser.
 5. System according to claim 2, in which said thermal regulation circuit comprises a heat transfer fluid.
 6. System according to claim 5, in which at least one thermal regulation module comprises at least one pump.
 7. System according to claim 5, in which at least one thermal regulation module comprises at least one compressor.
 8. System according to claim 2, in which said thermal regulation circuit comprises air as heat transfer fluid.
 9. System according to claim 8, in which at least one thermal regulation module comprises at least one fan.
 10. System according to claim 1, comprising at least one frame adapted to receive a modifiable number of embedded electronic modules.
 11. System according to claim 1, in which said thermal regulation circuit comprises a two-phase heat transfer fluid.
 12. System according to claim 11, in which at least one thermal regulation module comprises at least one condenser.
 13. System according to claim 1, in which said thermal regulation circuit comprises a heat transfer fluid.
 14. System according to claim 13, in which at least one thermal regulation module comprises at least one pump.
 15. System according to claim 13, in which at least one thermal regulation module comprises at least one compressor.
 16. System according to claim 1, in which said thermal regulation circuit comprises air as heat transfer fluid.
 17. System according to claim 16, in which at least one thermal regulation module comprises at least one fan.
 18. Aircraft comprising the thermal regulation system according to claim
 1. 19. Aircraft according to claim 18, in which said thermal regulation circuit comprises a heat transfer fluid.
 20. Aircraft according to claim 18, in which said thermal regulation circuit comprises air as heat transfer fluid. 